1. Field of the Invention
The present invention is related to apparatus and method for draining stored power, especially to the apparatus and method for draining stored power of an EMI filter circuit.
2. Description of Related Art
Generally, the circuit for power supply usually includes an EMI (electromagnetic interference) filter circuit for eliminating EMI of the power and the signals. The EMI filter circuit has at least a capacitor. Sometimes, a user may get an electric shock because of the electric power stored in the capacitor. Thus, in the aspect of safety and stability, a bleeder (usually a resistor) is provided to the EMI filter circuit in order to drain the power stored in the capacitor when the circuit for power supply is not working.
In such a circuit, the bleeder is usually parallel connected with the EMI filter circuit. Thus, the bleeder may continuously consume the power stored in the capacitor even when the circuit for power supply is currently operating. Briefly speaking, the bleeder may cause unexpected power loss.